November 15, 2013

Photo Essay: West Basin Water Recycling Facility

So, after living in the LA area for a while, I know where our water comes from.

I know where it goes after we flush the toilet.

But what I didn't know was that a portion of that treated toilet water, instead of getting dumped a few miles out into the ocean, travels down a big pipe next door, to the West Basin Water Recycling Facility (an agency of the Metropolitan Water District of Southern California), which cleans it up even more for reuse.

By then, it's so pure, you can drink it, but regulations don't allow you to yet. Instead, the recycled water is used mostly for irrigation of public lands within Southwest Los Angeles County's West Basin district (Culver City, El Segundo, all around LAX, the South Bay, and even West Hollywood) and for industrial purposes at local oil refineries that rely on boilers and steam.

I went down to El Segundo to the West Basin Water Recycling Facility to see where it all happens.

The facility arose out of the water shortages in the late 1980s and early 1990s, when one of California's worst droughts ever induced water rationing and conservation.

LA still couldn't figure out how to collect our stormwater, but by the mid-90s, triple distilled water was being pumped into local golf courses and municipal parks, instead of using drinking (potable) water.

Since then, the West Basin water recycling business has grown, with additional facilities in surrounding areas, and processing water at its current capacity, with an obvious need for growth.

They're even working on removing the salt from oceanwater in their nearby desalination testing facility.

For the purification process at West Basin, once the water is pumped from Hyperion Wastewater Treatment Plant (six million gallons of it per year), it undergoes a three step process to render it reusable: micro-filtration, reverse osmosis, and UV light & peroxide treatment.

From the catwalks above, you can see the intake process...

...where some of the water is still...

...not all of its solids removed by the treatment plant...

...adding chemicals to initially treat it upon intake...

...which renders it a reddish brown, poo-like color.

It's foamy because of the residual phosphates in the wastewater, which come from the prevalent cleaning products used (dish soap, disinfectants, Scrubbing Bubbles) in the water that goes down the drain.

It's really foamy.

Once chemically treated, and some solids removed...

...and then funneled to an onsite solids processing center to be trucked away (twice daily!)...

...the water is pumped over to the micro-filtration station...

...where the once-filtered water passes through tubes filled with thousands of hollow fibers that look like straws...

...and strain out any dirt, bacteria, and even viruses.

You wonder how they keep the lines clean without regular flushing (which they do at Hyperion)...

...but West Basin has a relatively new facility...

...and the chemicals that get the water clean (including some nasty stuff like Memclean-C which is technically hazardous material you don't want to get in your eyes or dump down the drain)...

...also generally keep the pipes and tubes clean.

But even at this stage, the phosphates are still in there. The water is still foamy.

There's a lot that goes on at the El Segundo facility which I'm sure the tour groups like mine don't get to see, and it's hard to tell from the outside what all of the tanks and pipes and knobs do.

But inside all of that machinery, after the microfiltration, the water goes through a membrane filtration process, whose reverse osmosis removes even more bacteria and viruses, as well as salts and even pharmaceutical drugs (that usually get flushed down the toilet or dropped down the sink).

Finally, after the pressure filtration, the water is treated with UV light in combination with ozone, an unstable molecule that produces an oxidizing agent that's toxic to water-borne organisms, and is generally used as an FDA-approved anti-microbial.

It's the same ozone as in the "ozone layer," which protects our fair skin from harmful UV rays.

Used also in conjunction with hydrogen peroxide, the UV light destroys any remaining buggers left in the water...

...without leaving any kind of disinfectant aftertaste...

...rendering it, as they say, even more pure than your common LA tapwater. In fact, they assert, if you were to mix your tap water with their triple filtered water, you'd contaminate theirs.

But you're still not allowed to drink it. Unlike New York City, LA isn't exactly known for its tasty tap water. Sometimes, in restaurants, it tastes like the ocean. Blech.

Of course, as tour guests, we got to have a glass of the finished product while we were there. It tasted fake and slippery, like what water is supposed to taste like maybe, but never does.

After all, there's little to no naturally-occurring "pure" water on the planet. It's all got stuff in it. It has to go through all these chemicals and treatments and membranes and processes to take everything out - just to put it back into the ground.

Related Post:
Photo Essay: Hyperion Wastewater Treatment Plant

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